This invention relates generally to engine knock control, and more particularly, to an engine knock detecting system that can be digitally reconfigured to operate in different knock signal processing modes.
In recent years, internal combustion engines have been equipped with microprocessor based engine controllers that operate in conjunction with knock control systems to detect engine knock and restrict the knock to acceptable limits by adjusting spark timing or some other engine operating parameter.
A knock detection system is basically a signal conditioner that differentiates between a variety of signals that are detected by acoustic sensors attached to the engine. A problem that must be overcome by a knock detection system is to differentiate between the signals produced by different mechanical stimuli, such as a piston slap or a valve train event as opposed to combustion events that occur because of knocking.
A variety of different signal processing configurations have evolved to provide reliable means for detecting knock in different engine applications. Traditionally, the knock detecting configurations have been separately implemented to match the knock characteristics of different types of engines. This has led to a proliferation of different specific knock detecting systems with limited versatility and applicability. However, these prior art detectors are not capable of being fundamentally reconfigured to utilize one of a plurality of different signal processing modes so that the detector can be applied to a specific engine design in a mode that works best for processing the signal for that particular engine.
Consequently, there exists a need for a knock detecting system that can be digitally reconfigured to operate in different knock signal processing configurations for usage in a wide range of different engine applications.